Solar Terrestrial Activity Report

Last major update issued on November 20, 2012 at 05:45 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update November 1, 2012)] [Cycle 24 progress (last update November 1, 2012) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update November 1, 2012)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update November 1, 2012)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update November 4, 2012)]

[POES auroral activity level since October 2009 - updated October 7, 2012]
[Solar polar fields vs solar cycles - updated June 27, 2011]

Recent activity

The geomagnetic field was quiet on November 19. Solar wind speed at SOHO ranged between 350 and 444 km/s.

Solar flux measured at 20h UTC on 2.8 GHz was 133.9 (decreasing 7.7 over the last solar rotation). The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.5). Three hour interval K indices: 21212201 (planetary), 11212211 (Boulder).

The background x-ray flux was at the class B4 level.

At midnight UTC the visible solar disk had 12 spotted active regions (in 2K resolution SDO images).

Region 11611 [N12W83] was quiet and stable.
Region 11612 [N08W71] was quiet and stable.
Region 11613 [S24W45] decayed slowly and quietly.
Region 11614 [N14W35] decayed slowly and quietly.
Region 11616 [N18W03] decayed slowly and quietly.
Region 11618 [N08E25] developed further and has significant polarity intermixing. An M class flare is possible. The region produced the only noteworthy flare of the day, an impulsive C7.0 event at 02:29 UTC.
Region 11619 [N10W12] decayed significantly and simplified. There's weak polarity intermixing centrally.

Spotted regions not numbered by NOAA/SWPC:
S2055 [S27W13] gained tiny trailing spots and was quiet.
S2059 [N08E33] was quiet and stable.
S2062 [S12E69] was quiet and stable.
New region S2064 [S21E72] rotated into view.
New region S2065 [N04E05] emerged with tiny spots in an old plage area.

Coronal mass ejections (CMEs)

November 17-19: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.

Coronal holes

Coronal hole history (since October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

No obvious coronal holes are currently in or near Earth facing positions.

The above coronal hole map is based on a method where coronal holes are detected automatically. While the method may need some fine tuning, it has significant advantages over detecting coronal holes manually. The main improvement is the ability to detect coronal holes at and just beyond the solar limbs. Early results using this method for SDO images over a span of several weeks indicate a good match between coronal holes observed over the visible disk and their extent and position at the east and west limbs. Note that the polar coronal holes are easily detected using this method, the extent and intensity of both CHs are consistent with other data sources.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 20-22.

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.

Active solar regions

Click on image for higher resolution image) Compare to the previous day's image. 0.5k image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue (blue-green) is positive.

Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.

Active region	Date numbered detected	Spot count			Location at midnight	Area	Classification		SDO / HMI 4K continuum image with magnetic polarity overlay		Comment
		SWPC	STAR SDO				SWPC	STAR	Current	Previous
			2K	1K
11611	2012.11.07 2012.11.08	1	1	1	N11W84	0040	HSX	HSX			area: 0150
11612	2012.11.08	2	1	1	N06W71	0030	HRX	HRX			area: 0010
11613	2012.11.09 2012.11.11	2	3	1	S26W44	0080	CSO	CSO			area: 0180 location: S24W45
11614	2012.11.10 2012.11.11	5	10	5	N14W34	0060	DAO	BXO
11615	2012.11.11				N07W48						plage
11617	2012.11.13 2012.11.16				S18W59						plage
11616	2012.11.13 2012.11.14	9	12	2	N19W03	0100	CAO	BXO			area: 0010 SWPC data does not reflect reality
S2051	2012.11.14				S12W28						plage
S2053	2012.11.14				S33W20						plage
S2055	2012.11.14		6		S27W13	0000		BXO
11618	2012.11.15 2012.11.17	18	34	22	N09E28	0160	FAC	DAC			beta-gamma
11619	2012.11.15 2012.11.17	15	28	15	N10W11	0200	DSI	DHI			beta-gamma area: 0350
S2059	2012.11.16		14	3	N08E33	0050		CRO
S2060	2012.11.17				S13E23						plage
S2061	2012.11.18				S33E33						plage
S2062	2012.11.18		2	2	S12E69	0100		HSX
S2063	2012.11.18				S12W48						plage
S2064	2012.11.19		1		S21E72	0000		AXX
S2065	2012.11.19		3		N04E05	0000		BXO
Total spot count:		52	115	52
Sunspot number:		122	235	142	(total spot count + 10 * number of spotted regions)
Weighted SN:		85	151	88	(Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number):		73	82	78	k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for STAR SDO 2K, k = 0.55 for STAR SDO 1K

Monthly solar cycle data

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official SIDC international sunspot number is typically 30-50% lower. 2B) Boulder SN current month average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.